Underground Affection
by HVK
Summary: Finn's in a romance with his girl buddies, and they're doing the same with each other; he goes down to Beautopia to spend time with Susan Strong, the latest to join his love-buddies, and sometimes it's nice just know he isn't the last human, and there's a place where the last descendants of humans live. Plus, he likes how big and nice Susan is.


Finn/Susan is one of my ships that I don't actively do much for, but I really like it a lot and enjoy writing about it. I also like the idea that Susan is definitely not related to Finn except perhaps in the sense of them being from the same tribe or such, and that she's actually not much older than him and merely quite big for her age.

Also, polyamory mentioned, going with my recurring notion of Finn ending up in a easy-going romance with Flame Princess, Marceline and Princess Bubblegum, and the women here are also in a romance with each other.

* * *

The small boat (clumsily built but quite capable of floating on the water) touched against the side of Beautopia, and Finn stepped onto the metal surface of the raised platform that was Beautopia's most noticeable landmark.

Finn looked up, yellow-orange hairs slick against his cheek in the dampness of this enclosed space, and a thrill of significance went through him as he looked up, light flickering from flames against the surprisingly healthy water down here, and the heads of mutated hyoomans swimming around amiably, several of them waving to Finn for though he was not hyooman they knew that he was one of them.

Finn stepped forward, looking up high and not realizing that he hadn't been breathing until he sucked in a long breath purely out of reflex.

Long ago, Bubblegum had told him after that adventure nearly a year or two ago when he'd told her all about what had transpired down there and she had delved into whatever mysterious resources she had to uncover the truth of the lost or forgotten things their world held, Beautopia had been a beauty resort. A place for people to go and be made prettier and healthier or at least feel prettier about themselves. And more, it was a place for _humans_, built long before the other people of Ooo had arrived from where they had been before. (At least, that's how she put it. Bubblegum liked to go on for a while about how almost certainly the people of Ooo had mutated from humans altered by exposure to the mutagenic weapons used in the Great Mushroom War, with many animals as well, but Finn honestly lost the thread when she really started getting going. On the bright side, Bubblegum never minded when this happened, knowing that Finn did his very best to keep up, and she dumbed it down as best she could.)

Beautopia had been _made _by humans. Finn swallowed, trying to process the point. He took a step and in the clamor of shouting and talking and laughing and happiness from the scores of hyoomans going about their business, the sound was swallowed up.

He knew humans had made things. He had seen the empty cities, the burned-out husks of places that had been forsaken and desolate ages before his most distant ancestors had ever been born, and because of that deadness the idea of human artifice had always seemed distant and ridiculous, like a bad joke that wasn't funny and was just mean-spirited. Those places were dead and any spirit they had gone for a very long time. They didn't _feel _like the lands of his people.

Standing here, in a city alive with a society and people that were very much descendants of humans (if not just seriously mutated humans themselves), he had to just look at it, the stone and metal and fire, this embodiment that said to the world that humans had been here and their children still lived here.

Finn had to smile. It felt beautiful, like when he was watching Bubblegum so deep into the science and the invention that she loved so much that she almost stopped being just a person at all but became a living avatar for Science, or like when he stood at the churches dedicated to the many aspects of Glob and the spirit of belief was in full force, hot and fiery and _real_.

He wandered past a few hyoomans that had swam up just to see if it really _was _Finn (for Finn's legend had spread down here, not his exploits of heroism but just the hyoomans being awed by the existence of a non-mutated human in the look of their ancestors and a very few unmutated exemplars) and sat down at a bench, just sitting there and smiling at nothing. The hyoomans looked at him curiously, chirped in satisfaction at his human-ness, and walked back into the waters to tend to their own affairs.

Finn sat there for a long time; he didn't know how long, not without the sun or devices to tell him the time, just sitting on the padded bench with his hands on his knees, wiggling around and humming contently to himself. He simply sat, and waited, and looked for a familiar hulking shape.

It might have been half an hour, it might have been longer or shorter. Finn didn't know. He tilted his head and smiled brightly as he saw the hyoomans unconsciously parted for a much larger shape to pass through them, big and curvy and more cute than beautiful. The hyoomans weren't exactly small, the largest of them towering over Finn or even his friends had they been there with him, but this woman was at least twice the side of even the tallest of them, and quite wide as well; Susan Strong, Finn concluded with a grin, was definitely a sight to see.

He stood up and pattered over one of the nailed mash-ups of wood some enterprising hyoomans had built as a bridge, and Susan looked up with her nostrils flaring, perhaps smelling him. A thick blond ponytail, longer than his entire arm, flopped over a broad shoulder extending out of the tattered armhole of the soft furs she wore. A face much rounder than Finn's and with scars of her own focused on Finn, and a wide mouth opened in delight; Susan burbled out an incoherent greeting in the private language of the hyoomans, and she remembered herself just in time. "Finn!" She said, her voice halting briefly over the unfamiliar language Finn and Jake had taught her (and she was so much smarter than she seemed, for as innocent and unintelligent as she acted a fool would never have been able to coherently speak a totally foreign language in such a short time), and waved to her. Her arm, thick and soft and with surprisingly little muscle definition for all her bulk, raised up in a jaunty wave.

The ground, though it was metal and stone, trembled slightly as she strode through the crowd to Finn, the hyoomans getting out of her way and jumping into the water in order to avoid getting accidentally thrown out of the way or smashed underfoot. The water rippled, both with evacuating hyoomans and the minor shockwaves of Susan's girth getting around.

Susan hopped over the bridge as she approached it, and Finn stepped aside as she easily cleared it, her landing causing a fairly violent impact. "Hey ya, Susan-fusing," Finn said cheerfully, and giggled at the rhyme he had made.

Susan, looming over head like an extremely pretty giant woman (or girl, Finn had no idea how old she was in spite of her size), tilted her head politely. She frowned thoughtfully, trying to figure out what Finn meant by that. She understood his words well enough, but she wasn't so good at translation at times. Deciding that she liked how it sounded even if it didn't really make sense, she giggled appreciatively. "Cutie," she said, leaning down enough to pat him on the head. Her shadow eclipsed his smaller body, swallowing up his shadow as well. The implications did not go amiss to a hyooman who happened to be watching this and took an interest in metaphysics, and scampered off to gossip to all her friends.

Finn smiled up at Susan, holding up his hand for a high five and stepping closer. He paused as he realized he was too close to her now for her to see him under her own girth; she looked bigger than a tree from the forests of the Grasslands here, and he definitely couldn't see her face over the very impressive expanse of her bust. Susan giggled, blushing hard at this, and stepped back a bit. Noticing Finn's gesture, she raised her hand and leaned down as far as she could without actually sitting down. Gingerly, so as not to hurt the relatively tiny boy, their hands met with a gentle smack. Though her hands were very small for her size (almost comically so), his entire hand still fit neatly into her palm, and Finn found that interesting. For all her size and strength Susan didn't intimidate him, and Finn smiled up at her again.

Susan smiled back, her lips a bit crooked at one corner, a shy and awkward expression as though she suddenly wasn't sure how to present herself or how to make herself look and she was inwardly having a freak-out over it. Her hands went to the small of her back, and she made a nearly hypnotic metronome as she swayed back and forth, anxious and endearing. Finn smiled at her and gave her a reassuring pat on the leg, just barely above her knee and as high as he could reach while standing on his tippy-toes.

His hand sank against her toned thigh for a moment, so soft was she. Susan trembled, giggling and blushing intensely, her hands up to her face in a shy grin, and Finn's face felt so warm now, and her body so invitingly warm and big, like a big bed that he could just crawl into and go to sleep on forever. He giggled too, and the two of them made a pleasant song when their giggling mixed.

Susan reached down, and after a moment of consideration over the best way to reciprocate, patted him on the head. Her fingers squeezed under his hat affectionately, reaching against his hair. Finn felt young suddenly, very young indeed, like a few years ago when he had no idea how to show a crush or act on it or anything about how to act around a girl when romancing was happening, and in one of those shows of keen awareness that was becoming more common as he grew older, he thought that _Susan _looked just as awkward and hopelessly confused, aware of her inexperience and close to self-conscious panic.

Her face looked younger than his, with none of the facial development he saw in Marceline or Bubblegum's faces. For a moment Finn thought that for all her size, maybe Susan was a whole lot younger than she looked, and not too much older than he was.

Finn hadn't really thought about that before. He reached up too, his hand fastening over her wrist. He squeezed, and it didn't matter that her wrist was nearly wider than his whole hand; Susan flushed, grinning awkwardly down at him, but she looked happy.

Finn walked, still holding her hand, and he kept a firm grip on her as he walked. For a moment, he felt the resistance of her massive body there, immobile and unmoving, and then her legs shifted, and she was walking after him, meekly letting him lead her on. Finn chuckled, unaccountably awkward about leading a girl more than twice his size like she was a school-pup who was afraid of looking silly on her first day.

"Come on," Finn said, encouragingly. "Where's your house again?"

Susan brightened. She adjusted her grip, spirited by Finn pointedly passing the responsibility of leading to her again, and she eagerly moved forward, pulling Finn along. He let out a startled squeak as he dangled a few feet above the ground, his feet limp and legs struggling for footing. Looking down and realizing that Finn was at waist-height now, the difference between them so pronounced that they couldn't hold hands and walk without some accommodations (not, as they had found on other occasions, that it wasn't worth the effort). Susan considered the problem for a moment, and then her shoulders shrugged like the exercises of mountains. She tugged Finn up, catching his rounded butt on the broadness of her forearm, and tugged him into her side. He giggled as softness pressed on him from all sides, her right breast soft against his legs and torso, and her bicep easily wider than he was and cushioning his back. He hugged her from the side, affectionate and smiling. "You give the best hugs and carries, Susan!"

Susan smiled down at him, giving him a little arm-squeeze like a hug in miniature. "Thankies, Finn!"

She set off at a long stride, moving quick and powerfully; Finn had been carried by girls before, and he'd been much higher than this with Marceline, but he'd never been this high up while still being technically on the ground, or being surrounded by… he blushed, so much _female_-ness. The all-encompassing presence of her body was definitely having an effect on him.

Susan was polite (or perhaps just even more naïve than him) not to notice or comment. She felt him moving against her, though, and her lips twitched almost slyly. It was such an unexpected emotion from her that Finn wasn't sure if he had seen it or not.

They passed bridges and ladders (made to suit her size, of course; she was to the hyoomans what Finn was to all of Ooo, and her people were willing to indulge her) until they came to a large building seemingly hammered right into the structure of Beautopia; shaped a little bit like a big bell, several windows glowing from behind with electric light (and Finn, having been treated to difficulties with harnessed energy during an adventure with Bubblegum a short while ago, wondered where they got it down here), and Susan moved easily though a hatch-style door made for her dimensions.

She set him down on a floor made soft by layers of furs; from the wild and mean look of a lot of them, Finn guessed that Susan was getting braver and willing to go outside of her underground home to fight monsters and skin them as trophies. He giggled and laughed, clapping and bouncing in excitement of his fellow human doing such a thing.

Of course she was human; it was amazing, thinking that. It didn't really matter, he supposed, all of his other friends were definitely not human, but it was really nice just knowing that he _wasn't _all alone after all.

Finn followed Susan to the Susan-sized table in the middle of the round-shaped room her, just near a ladder that he knew led up to her bedroom (having been there himself on a few _extremely _memorable occasions), pulling up a tall chair so he could sit there. He felt embarrassed for a moment, feeling like a little baby at the adult's table, but this quickly subsided when Susan passed a bowl full of meat from the other night to him. He happily ate it up in a few bites (meat and bones and all), hungry from the journey down here.

"How are friends?" Susan asked, propping up an elbow on the table and smiling at him.

"Good," Finn said, smiling at her. "Jake's keeping people from knowing about this place so nobody bugs your peeps. Bubblegum probably would wanna come down here, but you sorta freaked her out with the trying to eat the Candy Kingdom thing…"

Susan pouted. "Long time ago. She still mad?"

"Not mad… uh, yeah, she got ticked, but I think it's more like she's scared."

"Aw, but she talks to Susan all the time!"

"I dunno. Guess it's cause you're cool, but she doesn't know about your people being cool too."

Susan nodded thoughtfully.

"Anyway, I hear Marcy came down here the other night to hang-"

"Yep," Susan said. "She... um, what is words…?" She fumbled her hands around, trying to contrive something. "Fingers… sounds, really nice sounds?"

"Music?" Finn guessed. Susan nodded eagerly. "Oh! Um… she did a concert or something down here?"

"Yes!"

"Oh." Finn giggled appreciatively. "Marcy does the best music!"

"Yes!" Susan said again. Repeating herself like this seemed to amuse her, and she giggled loudly.

"Um… I think Flame Princess would like to come down here and hang out with us," Finn said, speaking carefully. "You know, the next time me and you and Marcy and Peebee do stuff together."

Susan looked worried. "She… scary…"

"Aw, don't be like that, Susan! She's really nice! When she's not yelling. Or having a mood swing. Or gets mad over something she doesn't understand… or is turning into a giant fire-girl because it's funny when people freak out over that… um, I'm not helping, am I?"

"Nuh-uh," Susan said, looking a little paler than normal.

Finn snorted. "C'mon, be a hero! Be cool! Do better by your alignment."

Susan tilted her head. "How you know Susan's alignment?"

"'Cause you hang around helping people all day. Seems pretty Good to me!" Finn didn't add that he was pretty sure that Susan was Neutral Good, because he wasn't sure Susan had made a study of the nine alignments yet, though he was hoping to introduce her to some good gurus of that stuff.

Susan puffed a cheek out. "…Susan will try," she said after a moment.

Being with Susan like this was all part of The Arrangement, Finn had a moment to think about. It wasn't a formal agreement or anything like that, though he gave it unnecessary capital letters. In effect, considering the different girls he had grown close with over the years, the closest of friends with Bubblegum and Marceline and Flame Princess and Susan, and now rather something more with all of them, it had simply come to pass that they had become something of an odd family, and the girls were as affectionate and romantic to each other as they were with Finn (a few speed bumps between their different personalities notwithstanding).

(Polyamory was not, in Ooo, a taboo or even mildly unusual situation, especially among princesses and royalty. Or, for that matter, endangered species. Bubblegum might have insisted on Finn having multiple partners just on the change that his people might endure for another generation or two if all things went well; she seemed to take extinction as a personal offense. The concept of sexual taboos, for that matter, was a totally alien concept to Ooo, provided that there was consent on all sides. Finn had run across the concept of sexual taboos, and wasn't sure what to make of the idea. It was just so… _odd _compared to what he had grown up with.)

"Good enough!" Finn said cheerfully. He pushed the bowl of food away, scooting his chair out. "Whatcha wanna do now."

Susan thought about. "Susan find crocodile-dragon that breath fire and spit acid and insult fluffy people.""

Finn gasped in horror. "They _insult fluffy people!?_ Susan, this is an affront to our alignment! We gotta go and smash 'em good!"

"What is affront?" Susan asked.

"I dunno. But it sounds cool!"

Susan stood up and picked Finn up, deciding that sounded fine. She held him up to her face, and he suddenly felt small and tiny in a very good way, with this beautiful giant girl holding him up like this, her massive strength evident in even the slight touch on his arms. Impulsively, Finn kissed her nose, his lips pressing warmly against the broad shape just around her nostrils. Susan giggled, and suddenly squeezed him to her so powerfully that the breath was shoved out of him even as she kissed him, her mouth swallowing up his own mouth and a good part of the lower portion of his face, and briefly Finn felt something wet and slick and intense meeting his tongue, sliding sweetly and gingerly…

And then they parted, Susan giggling and placing him down, striding merrily out the door as Finn gaped. He didn't think he imagined her hips, already noticeably with them being slightly wider than her already big shoulders, swinging invitingly with her steps. He recovered himself, giggled helplessly, and followed after her.


End file.
